Polymethine dyes



Patented June 11, 1940 UNITED STATES PATENT OFFICE POLYMETHINE DYES Oskar Riester, Dessau-Ziebigk, Germany, assignor, by mesne assignments, to General Aniline & Film Corporation, New York, N. Y., a corporation of Delaware No Drawing. Application February 28, 1938, Se-

rial No. 193,083. In Germany March 4, 1937 Claims. (Cl. 260-240) This invention relates to new dyes and a new acylamino-, aryland phenylene-groups. Also method for preparing those dyes. unsaturated substituted aliphatic-amino alde- It is known that yellow dyestuffs can be obhydes may be used. tained from acetone dicarboxylic acid and its The following examples illustrate the inven- 5 esters with aromatic aldehydes in presence of tion butthey are not intended to limit it thereto: 5'

mineral acid. These dyestuffs are only yellow Example 1. A solution of 2 mol of'p-dimethyland of little intensity. aminobenzaldehyde and 1 mol of acetone dicar- An object of the present invention is to proboxylic acid in a mixture of 5 mol of acetic vide a new process for the preparation of dyes a hyd de a d 1 mol of py is heated or 2 of the polymethine type. hours at 35 C. The violet dyestuff thus ob- 10 A further object of this invention is the protalned has the following structural formula vision of polymethine dyes, which contain in 0 their molecule a keto group in the center of the ll polymethine chain and constitute a completely (OH3)2NC OB CH C CH-CBGN(OHS)2 1 new class dyestuffs- Example 2.2 grams of para-methoxyindole- Other ob ects of the invention will appear 2-monomethine aldehyde andl gram of from the fol o d iption. tone dicarboxylic acid are dissolved in 5 cc. of The new polymethine dyestuffs belong neither acetic anhydride.- This solution is then heated to the basic nor to the acid dyestuffs and are of for 1 hour at 50 C. The intensely red dyestuff importance in the dyeing art. They are suitable thus obtained has the following formula 20 cm om cm on.

:00 00B; i c=cn---on=on-d-on=onon=o 25 (BB. (I311:

for example for dyeing acetate silk. Moreover The starting aldehyde is obtained in the followthese dyestuffs may be used for sensitizing phoing manner (see German Patent No. 615,130): 30

tographic emulsions and for producing bleach- Methylformylaniline is condensed with phosing-out layers. The sensitizers are characterized phorus oxychloride while stirring. To the mixy p a y narrOW Se s t at n. e bleac ture there is added o-dichlorbenzene and with insut a s p par d y using these d s ar cooling 1.1.3-trimethyl-2-methylene-6-methoxy- Characterized by their gr eat rapidity in forming indoline. After the reaction is finished steam is a p passed into the mass. The remaining aldehyde I have found that m presence of acetic is dried and recrystallized from ligroin.

anhydride with or without solvent 2 mol of a A photographic silver bromide emulsion sensisubstltuted alflehyde contammg mtrogfm may b tized with this dye shows a sensitizing maximum condensed with 1 mol of acetone dicarboxylic t 5750 A U Th d t if d f 1 40 acid with-elimination of 2 mol of carbon dioxide e yes u or exam?) to produce dyestuffs more deeply colored than acetate silk t nts which resemble those obtained those refe d to above with rhodamine on cotton staple.

The aldehyde may contain an aromatic ring Example 3.-A solution of 2 grams of indoleor a heterocyclic nucleus derived for example 2-monomethinew-aldehyde Ob ed in a man- 45 from thiazole, indole, oxazole, selenazole, thiazoner analogous to that as described in Example 2 line, thiodiazole, quinaldine, lepidine, imidazole by means of 1.1.3-trimethyl-2-methy1ene-indoor the like. These bases maybe substituted line) and2 grams of acetone dicarboxylic acid with all known substituents such as follows: in a mixture of 6 cc. of acetic acid and 6 cc. of

59 alkyl-, alkoxy-, thioalkyl-, amino-, alkylamino-, acetic anhydride is heated for half an hourat C. The red dyestufi thus obtained has the following formula A photographic silver bromide emulsion sensitized with this dyestuff shows a sensitizing maximum at 5750 A. U.

Example 4.A dyestufi? from N-methylbenzthiazole--2-monomethinew-aldehyde prepared in a similar manner as described in Example 2 has the following structural formula The starting aldehyde is produced in the following manner (see French Patent No. 808,598): 2-acetanilidovinylbenzthiazole methiodide is suspended in absolute ethyl alcohol and a concen- A photographic silver bromide sensitized with this dye shows a sensitizing maximum at 7000 Example 6.--From tetrahydroquinoline-N-propenal prepared asdescribed in French Patent No. 828,384 there is obtained in a similar manner as described in Example 2 a yellow-red dyestuff of the following formula Absorption maximum about 5100 A. U.

A photographic silver bromide emulsion sensitized with this dyestulf shows a sensitizing maximum at 5300 A. U.

Example 7.From dihydro-w-methylindole-N- pentadienal produced in the manner disclosed in German Patent 218,616 there is obtained in a similar manner as described in Example 3 a blue-violet dyestufi of the following formula Example 8.-From dimethyl-N-propenal there is produced in a similar manner as described in Example 1 a yellow dyestuff of the following formula Example 9.From formyl-tetrahydroquinoline and acetone dicarboxylic acid in acetic acid and acetic anhydride there is obtained a lemonyellow dyestulf of the following formula Example 10.--From N ethyl thiazolene 2- monomethine-w-aldehyde (obtainable in a manner analogous to that as described in French Patent No. 808,598 by hydrolyzing acetanilidovinylthiazoline ethiodide by means of potassium hydroxide) there is produced an orangeyellow dyestuff of the following formula Example 11.From N-ethyl pp-naphtho-oxazole-2-monomethine-w-aldehyde (obtainable in a manner analogous to that as described in French Patent No. 808,598 by alkaline hydrolysis of acetanilidovinyl-[ifi-naphtho-oxazole ethiodide) there is produced a yellow dyestuff of the following formula 0 o w o=oa-omon-ti-omon-omo m N/ \N (5,115 la s Example 12. From N-ethyl p-methyl quinaldine-Z-mOnomethine-w-aldehyde (obtained in a manner analogous to that described in French Patent No. 808,598 by hydrolyzing anilidovinyl G-methyI-quinoline ethiodide by means of sodium hydroxide) there is produced a yellow-red dye: stuff of the following formula H3O A O l on. o \N/-CH-OH OHCOH-OHGH- \N/ I 32 15 2H6 I claim: 1. A process for the preparation of a poly- /HH1 c-o methine dye corresponding with the following structural formula which comprises condensing two mol of p-methoxyindole-2-monomethine-w-aldehyde with one mol of acetone dicarboxylic acid in the presence of acetic anhydride.

2. A process for the preparation of a polymethine dye corresponding with the following structural formula which comprises condensing two mol of N- methylbenzthiazole-Z monomethine-w-aldehyde with one mol of acetone dicarboxylic acid in the presence of acetic anhydride.

3. A process for the preparation of a polymethine dye corresponding with the following structural formula which comprises condensing two mol of tetrahydroquinoline-N-propenal with one mol of acetone dicarboxylic acid in the presence of acetic anhydride.

4. A process for the preparation of polymethine dyes which comprises condensing two mol of a compound corresponding with the following structural formula A(CH) nCHO where n is a member of the group consisting of O and an integer;

OOH:

A is a member of the group consisting of A (CH) nCHO Where n is a member of the group consisting of 0 and an integer;

A is a member of the group consisting of /N, Narylene, B N-, and IIIQC= R R R a where R is an alkyl, and B and D represent the atoms necessary to form a member of the group consisting of a heterocyclic nucleus and a substituted heterocylic nucleus, with at least one mol of acetone discarboxylic acid in the presence of an indiiferent solvent and acetic anhydride.

OSKAR RIES'I'ER. 

